1. Field of the Invention
The present invention generally relates to an imaging device, and more particularly to a method of calibrating luminance and contrast for the imaging device.
2. Description of Related Art
Automatic exposure (AE) and autofocus (AF) have become indispensable to modern cameras and have deterministic influence on resultant capture image. According to AE, the camera can automatically adjust aperture and shutter speed based on light-meter readings. According to AF, the camera can automatically focus the lens based on measuring contrast in a scene.
However, it is observed that luminance or contrast reading value is not constant but varies depending on lens position of the camera. As a result, the automatic exposure or autofocus oftentimes cannot perform as expected.
For the reason that conventional automatic exposure and autofocus in the camera could not effectively capture an image with satisfactory quality, a need has arisen to propose a novel method for calibrating the luminance or contrast readings.